1. Field of the Invention
The present invention relates to a medical instrument provided with image pickup means for observing the interior of the body of a patient.
2. Description of the Related Art
As is generally known, endoscope apparatuses, which are medical instruments, are provided with an image pickup apparatus which is image pickup means, designed to be introduced into the body cavity of a patient and carry out various kinds of inspections and treatment or the like of affected areas in the body based on observed images photographed by the image pickup apparatus. Examples of such endoscopes include those introduced into digestive organs such as esophagus, stomach, large intestine, duodenum, which are tube cavities in the body from the oral cavity or anus and those introduced into the abdominal cavity from the vicinity of the umbilical region by puncturing through the body wall.
In a medical endoscope apparatus, smear in the body such as mucous membrane, dirt, blood may stick to an observation window of the image pickup apparatus or moisture may stick to the observation window of the image pickup apparatus due to a highly humid use environment in the body, causing window fogging. Thus, such adherents may degrade visibility and prevent clear photographed images from being acquired. Therefore, various proposals to remove adherents stuck to the observation window of the image pickup apparatus have been conventionally presented.
For example, Japanese Patent Application Laid-Open Publication No. 8-29699 discloses an image scope provided with a wiper that wipes dirt off the outer surface of an objective lens. Furthermore, for example, Japanese Patent Application Laid-Open Publication No. 5-103748 discloses a catheter apparatus for endoscopy provided with a catheter body in which an endoscope whose observation window and channel opening are exposed to the distal end portion is inserted.
The conventional catheter apparatus for endoscopy forms a shielding member at the distal end portion of the catheter body for shielding at least part of the opening of the channel of the distal end portion of the endoscope or the like and is also provided with a locking mechanism as restricting means for restricting relative rotation between the endoscope and the catheter body and discloses a technique capable of opening/closing the opening of the channel as required. Furthermore, a wiping member such as buff is provided on the back of the shielding member so as to allow the wiping member to wipe away dirt or the like stuck to the observation window and illumination window of the endoscope.